sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

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Today's topics:

* Incorrectly marked transistors? - 20 messages, 5 authors
http://groups.google.com/group/sci.electronics.repair/t/1e12bfd4ba9ca5dd?hl=en
* CR2023? CR2032 Batteries - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/8e15ac1d36a61277?hl=en
* Laser fuser thermal switches? - 3 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/3e3bc34da4e7c0cf?hl=en
* Why would a DECT Panasonic cordless phone keep losing the wireless link? - 2
messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/cc34e585e15dfff5?hl=en

==============================================================================
TOPIC: Incorrectly marked transistors?
http://groups.google.com/group/sci.electronics.repair/t/1e12bfd4ba9ca5dd?hl=en
==============================================================================

== 1 of 20 ==
Date: Tues, Jan 14 2014 10:54 am
From: Cydrome Leader


Phil Allison <phil_a@tpg.com.au> wrote:
>
> "Gareth Magennis"
>>
>>
>> I recently bought some TIP35C transistors from Farnell UK. Just before I
>> fitted one to an amplifier I thought I'd just check the pinouts.
>> Good job I did because instead of BCE they measured BEC.
>>
>
> ** That is just not possible.
>
> The middle leg is always the collector and metal tab used for heatsinking.
>
> FFS - get an ohmmeter and verify that simple fact.
>
> Seems your dopey microprocessor ( ie software) based POS has gone ape and
> confused Collector with Emitter.

Agreed.

those component testers are sketchy in that you have no idea what they are
doing or how they draw conclusions.






== 2 of 20 ==
Date: Tues, Jan 14 2014 3:39 pm
From: Uffe Bærentsen


Den 14-01-2014 14:09, Phil Allison skrev:

Hi Phil

Interesting to read this:

>>> ** Testing the Hfe of *power transistors* is a whole DIFFERENT ball
>>> game to small signal devices.
>>>
>>> That is why I designed a special device just for power devices -
>>> published as a project in Electronics Australia magazine in May 1988.
>>>
>>> Test are done at a constant Ic of 0.6 amps instead of some fixed and way
>>> too small Ib.
>>>
>>> Results are spot on and match maker's data which follow the same idea.
>>>
>>> Works fine with TV horizontal output devices, power darlingtons and any
>>> BJT rated for high power.

Is there any chance that you would have an electronic copy of this that
you would be willing to share?
Since I'm in Denmark which happens to be on the other side of the planet
compared to Australia, magazines from Australia are kind of rare around here

For reply please remove this from my mail adr: _FJERNES_ (the
underscores need to be removed as well).


--
Uffe




== 3 of 20 ==
Date: Tues, Jan 14 2014 4:13 pm
From: "Gareth Magennis"




"Phil Allison" wrote in message news:bjkr7sFkgn8U1@mid.individual.net...


"Gareth Magennis"
> "Phil Allison"
>>>
>>>>>
>>>>> I recently bought some TIP35C transistors from Farnell UK. Just
>>>>> before I fitted one to an amplifier I thought I'd just check the
>>>>> pinouts.
>>>>> Good job I did because instead of BCE they measured BEC.
>>>>>
>>>>
>>>> ** That is just not possible.
>>>>
>>>> The middle leg is always the collector and metal tab used for
>>>> heatsinking.
>>>>
>>>> FFS - get an ohmmeter and verify that simple fact.
>>>>
>>>> Seems your dopey microprocessor ( ie software) based POS has gone ape
>>>> and confused Collector with Emitter.
>>>>
>>>
>>>
>>> I did suspect my dopey checker, but even with a fresh battery it ALWAYS
>>> reads EXACTLY the same,
>>
>>
>> ** ROTFL - since when is THAT any reason to trust it ?????
>>
>> " It must be right cos it always tells the SAME lie "
>>
>> Wot an idiot you are.
>>
>>
>>> which is: 3 of them measure BEC with an Hfe of 5, the other one BCE
>>> with an Hfe of 20.
>>
>> ** No fooling.
>>
>> BJTs have very low Hfes if C and E are reversed.
>>
>> Like 2 or 3 instead of 100 or 200.
>>
>> They *also* show very low readings if the meter is no fucking good.
>>
>> See how that might be confusing ???
>>
>>
>>> (All tabs connect to centre pin)
>>
>>
>> ** Then there is simply **NO** problem with the devices.
>> -------------------------------------------------------------------
>>
>> YOU are the problem with your dopey meter that is not able to tests power
>> BJTs properly.
>>
>> FYI Try it with a TV horizontal output transistor like the BU208.
>>
>>
>>> The replacements I finally got from Farnell with a different batch code
>>> measure an Hfe between 40 and 70.
>>
>>
>> ** Testing the Hfe of *power transistors* is a whole DIFFERENT ball
>> game to small signal devices.
>>
>> That is why I designed a special device just for power devices -
>> published as a project in Electronics Australia magazine in May 1988.
>>
>> Test are done at a constant Ic of 0.6 amps instead of some fixed and way
>> too small Ib.
>>
>> Results are spot on and match maker's data which follow the same idea.
>>
>> Works fine with TV horizontal output devices, power darlingtons and any
>> BJT rated for high power.
>>
>>
>>
>>> I know Hfe is kind of meaningless on these types of checker voltages,
>>> but was still wondering why the checker would give a different pinout
>>> result rather than fail the device.
>>
>> ** Cos it is using the wrong approach for power BJT devices.
>>
>>> I suspect all 4 of the "old" transistors are faulty,
>>
>> ** Bollocks.
>>
>> You have a **fucking useless** meter that only works with those examples
>> of power BJT devices that exceed maker's specs at the low end of the Ic v
>> Hfe range.
>>
>> Take a LOOK at some ACTUAL power BJT data sheets some time !!!!!!!!!
>>
>> Hfe is NOT a constant !!!!!!!!!!!!
>>
>
> Yes I know Hfe is not constant, that is why I said the reading is
> meaningless on such a low voltage checker.
>
> I do not use this device to measure Hfe,


** No, but the dopey fuckin meter IS doing just that.

How do you imagine it tells C from E ??

Might it not use the Hfe test to do it ???????????
-------------------------------------------------------

How would YOU tell C from E with no other data ?


> I usually just want to know if a transistor is bad, what pinout it is, and
> whether or not it tests on this meter in the same ballpark as a known good
> one.

** Fraid you stupid POS meter CANNOT do that for power BJTs.

HOW MANY TIMES do you have to be FUCKING TOLD ???????



> These 4 "faulty" transistors ..

** FFS - YOU are the ONLY faulty thing !!!!!!!!!!

THAT STINKING POS CANNOT TEST POWER BJTs !!!!!!!

It is a SMALL SIGNAL device tester.

READ the fucking spec sheet for it - DICK HEAD !!

The throw that POS in the bin and DO the TEST ANOTHER WAY !!!!

Fuck you are DUMB !!!!!!!!!!



.... Phil




Phil. I know how my test equipment works, I use it every day.

I know when I come across an anomaly. That comes with an intimate knowledge
of how your test equipment works.


Gareth.





== 4 of 20 ==
Date: Tues, Jan 14 2014 4:31 pm
From: "Phil Allison"



"Gareth Magennis"


> Phil. I know how my test equipment works,

** Like hell you do !!!!!!!!!!

And you have NO FUCKING IDEA how to test a power BJT.


> I know when I come across an anomaly.

** You think the sky is falling and run around like a headless chook.



FYI: Do you have two DC power supplies?

Use one to provide a collector current of say 0.5 amps.

Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.

The ratio of currents will give you the correct Hfe for most power BJT
devices.



.... Phil









== 5 of 20 ==
Date: Tues, Jan 14 2014 4:46 pm
From: "Phil Allison"



"Cydrome Leader"
> Phil Allison
>> "Gareth Magennis"
>
>>>
>>> I recently bought some TIP35C transistors from Farnell UK. Just before
>>> I
>>> fitted one to an amplifier I thought I'd just check the pinouts.
>>> Good job I did because instead of BCE they measured BEC.
>>>
>>
>> ** That is just not possible.
>>
>> The middle leg is always the collector and metal tab used for
>> heatsinking.
>>
>> FFS - get an ohmmeter and verify that simple fact.
>>
>> Seems your dopey microprocessor ( ie software) based POS has gone ape and
>> confused Collector with Emitter.
>
> Agreed.
>
> those component testers are sketchy in that you have no idea what they are
> doing or how they draw conclusions.
>

** Exactly.

The tester that Gareth has operates at very low currents and voltages - a
couple of mA at most.

Some power BJTs lose all current gain at that level, showing Hfes of maybe 1
or 2.

Very likely, this is fooling his meter into giving wrong info about C and E
terminals - since the reading is like that when C and E are reversed.

The tester I designed operates from a 12V supply and one sets the base drive
current with a wirewound pot to get 0.5 amps from the supply.

A calibrated scale gave the base current as a ratio to that current - or
Hfe.

Small signal "Beta" testers are USELESS for this job.


.... Phil








== 6 of 20 ==
Date: Tues, Jan 14 2014 4:46 pm
From: "Phil Allison"



"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL















== 7 of 20 ==
Date: Tues, Jan 14 2014 4:46 pm
From: "Phil Allison"


"William Sommerwerck"


** FUCK OFF MORONIC TROLL



"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL























== 8 of 20 ==
Date: Tues, Jan 14 2014 4:51 pm
From: "Gareth Magennis"




"Phil Allison" wrote in message news:bjm352Ft22pU1@mid.individual.net...


"Gareth Magennis"


> Phil. I know how my test equipment works,

** Like hell you do !!!!!!!!!!

And you have NO FUCKING IDEA how to test a power BJT.


> I know when I come across an anomaly.

** You think the sky is falling and run around like a headless chook.



FYI: Do you have two DC power supplies?

Use one to provide a collector current of say 0.5 amps.

Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.

The ratio of currents will give you the correct Hfe for most power BJT
devices.



.... Phil




Phil, I am not at all interested in finding the accurate Hfe of a
transistor.
All I need to know is if it works within design parameters, or it doesn't.

If it doesn't I will replace it with something that does.

I will leave Farnell to ensure that the Hfe of the replacement device is
what it should be. That is what I am paying them for.
Otherwise I would have to charge my clients double the labour charge to
verify such things, and they would not be happy, and I would be out of
business very quickly.


Cheers,


Gareth.











== 9 of 20 ==
Date: Tues, Jan 14 2014 5:07 pm
From: "Gareth Magennis"






Phil, I am not at all interested in finding the accurate Hfe of a
transistor.
All I need to know is if it works within design parameters, or it doesn't.

If it doesn't I will replace it with something that does.

I will leave Farnell to ensure that the Hfe of the replacement device is
what it should be. That is what I am paying them for.
Otherwise I would have to charge my clients double the labour charge to
verify such things, and they would not be happy, and I would be out of
business very quickly.


Cheers,


Gareth.




Hmm, having said that, the whole thread is really about Farnell supplying
faulty parts and me identifying them with a Mickey Mouse component tester.

Allegedly.



Cheers,

Gareth.










== 10 of 20 ==
Date: Tues, Jan 14 2014 5:42 pm
From: Cydrome Leader


Gareth Magennis <gareth.magennis@ntlworld.com> wrote:
>
>
> "Phil Allison" wrote in message news:bjm352Ft22pU1@mid.individual.net...
>
>
> "Gareth Magennis"
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> .... Phil
>
>
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.

Are you confident your tester is performing tests within operating
parameters of your device under test?








== 11 of 20 ==
Date: Tues, Jan 14 2014 5:46 pm
From: "Phil Allison"



"Gareth Magennis"
> "Phil Allison" "Gareth Magennis"
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
>
> All I need to know is if it works within design parameters, or it doesn't.


** Then put some in an ampifier and see.


> I will leave Farnell to ensure that the Hfe of the replacement device...


** HUH ???

You are one arrogant pommy pig.

You have NOTHING to say there is ANY problem with the TIP35/36s you
were supplied.

You come here asking for advice - then you COMPLETELY IGNORE IT.

YOU need a fucking good kick RIGHT UP THE ARSE.

Fucking IDIOT.



.... Phil







== 12 of 20 ==
Date: Tues, Jan 14 2014 5:48 pm
From: "Phil Allison"



"Gareth Magennis"
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.
>
> If it doesn't I will replace it with something that does.
>
> I will leave Farnell to ensure that the Hfe of the replacement device is
> what it should be. That is what I am paying them for.
> Otherwise I would have to charge my clients double the labour charge to
> verify such things, and they would not be happy, and I would be out of
> business very quickly.



** HUH ???

You are one arrogant pommy pig.

You have NOTHING to say there is ANY problem with the TIP35/36s you
were supplied.

You came here asking for advice - then you COMPLETELY IGNORE IT.

YOU need a fucking good kick RIGHT UP THE ARSE.

Fucking IDIOT.



.... Phil











== 13 of 20 ==
Date: Tues, Jan 14 2014 6:07 pm
From: "William Sommerwerck"


"Gareth Magennis" wrote in message news:%alBu.3143$5p6.1736@fx25.am4...

> Hmm, having said that, the whole thread is really about
> Farnell supplying faulty parts and me identifying them
> with a Mickey Mouse component tester.

Correct. Please let us know if they turn out to be counterfeit.




== 14 of 20 ==
Date: Tues, Jan 14 2014 6:08 pm
From: "William Sommerwerck"


"Phil Allison" wrote in message news:bjm42pFt7d6U1@mid.individual.net...

"William Sommerwerck"

** FUCK OFF MORONIC TROLL

"William Sommerwerck"

** FUCK OFF MORONIC TROLL

"William Sommerwerck"

** FUCK OFF MORONIC TROLL

"William Sommerwerck"

** FUCK OFF MORONIC TROLL

"William Sommerwerck"

** FUCK OFF MORONIC TROLL


You should consider having a rubber stamp made. Preferably the self-inking
kind.
























== 15 of 20 ==
Date: Tues, Jan 14 2014 6:11 pm
From: "Gareth Magennis"




"Cydrome Leader" wrote in message news:lb4p2b$7fn$1@reader1.panix.com...

Gareth Magennis <gareth.magennis@ntlworld.com> wrote:
>
>
> "Phil Allison" wrote in message news:bjm352Ft22pU1@mid.individual.net...
>
>
> "Gareth Magennis"
>
>
>> Phil. I know how my test equipment works,
>
> ** Like hell you do !!!!!!!!!!
>
> And you have NO FUCKING IDEA how to test a power BJT.
>
>
>> I know when I come across an anomaly.
>
> ** You think the sky is falling and run around like a headless chook.
>
>
>
> FYI: Do you have two DC power supplies?
>
> Use one to provide a collector current of say 0.5 amps.
>
> Use the other to drive the base via a 1 kohm resistor so Ic is 0.5 amps.
>
> The ratio of currents will give you the correct Hfe for most power BJT
> devices.
>
>
>
> .... Phil
>
>
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.

Are you confident your tester is performing tests within operating
parameters of your device under test?




Of course I'm not, as you well know. It has a 9v battery which may or may
not produce higher test voltages.

That is not the point.
The point is I can do a direct A/B comparison between devices I know work
and the one in question.

If after years of doing this I come across a batch of transistors that seem
to defy all logic, then I will suspect those transistors as being faulty or
out of spec.
And, if those transistors are then replaced with a different batch from the
same manufacturer and they all test as OK, then my suspicions are confirmed.


This is not rocket science, it is just logic.


Cheers,


Gareth.













== 16 of 20 ==
Date: Tues, Jan 14 2014 6:11 pm
From: "William Sommerwerck"


"Phil Allison" wrote in message news:bjm41jFt74gU1@mid.individual.net...

> The tester that Gareth has operates at very low currents and
> voltages - a couple of mA at most.
> Some power BJTs lose all current gain at that level, showing
> Hfes of maybe 1 or 2.
> Very likely, this is fooling his meter into giving wrong info
> about C and E terminals -- since the reading is like that when
> C and E are reversed.

If that's true... Is there sufficient sample-sample variation for this to
occur?





== 17 of 20 ==
Date: Tues, Jan 14 2014 6:37 pm
From: "Gareth Magennis"




"Phil Allison" wrote in message news:bjm7m8FtseeU1@mid.individual.net...


"Gareth Magennis"
>
>
> Phil, I am not at all interested in finding the accurate Hfe of a
> transistor.
> All I need to know is if it works within design parameters, or it doesn't.
>
> If it doesn't I will replace it with something that does.
>
> I will leave Farnell to ensure that the Hfe of the replacement device is
> what it should be. That is what I am paying them for.
> Otherwise I would have to charge my clients double the labour charge to
> verify such things, and they would not be happy, and I would be out of
> business very quickly.



** HUH ???

You are one arrogant pommy pig.

You have NOTHING to say there is ANY problem with the TIP35/36s you
were supplied.

You came here asking for advice - then you COMPLETELY IGNORE IT.

YOU need a fucking good kick RIGHT UP THE ARSE.

Fucking IDIOT.



.... Phil


No Phil, you are one arrogant Ozzie twat for trying to hijack the thread to
promote your Hfe tester design.

Of which I am not in the least bit interested.


Cheers,


Gareth.











== 18 of 20 ==
Date: Tues, Jan 14 2014 7:07 pm
From: "Phil Allison"



"Gareth Magennis"


** You are liar and a prize cunt.

Fuck you.








== 19 of 20 ==
Date: Tues, Jan 14 2014 7:10 pm
From: "Phil Allison"



"Gareth Magennis"



> This is not rocket science, it is just logic.


** It is all false logic and pure bullshit.

The " Peak DCA50e " is useless for testing power transistors.

And YOU are just a another stupid, lying pommy cunt.



.... Phil









== 20 of 20 ==
Date: Tues, Jan 14 2014 7:11 pm
From: "Phil Allison"



William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


William Sommerwerck"


** FUCK OFF MORONIC TROLL



"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL

William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL

William Sommerwerck"


** FUCK OFF MORONIC TROLL



"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


"William Sommerwerck"


** FUCK OFF MORONIC TROLL

"William Sommerwerck"


** FUCK OFF MORONIC TROLL


























































































==============================================================================
TOPIC: CR2023? CR2032 Batteries
http://groups.google.com/group/sci.electronics.repair/t/8e15ac1d36a61277?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jan 14 2014 11:57 am
From: Michael Black


On Mon, 13 Jan 2014, stratus46@yahoo.com wrote:

>
> Today we received the 2032 cells from Digikey. 100 pcs Panasonic for
> $19.25.
>
> Don't pay those horrible drugstore prices.
>
I don't know. One drugstore here for a while was selling generic
batteries of that kind, relatively cheap. They may still do, and simply
moved them.

I can get them for fifty cents at a the local outlet of the Big Chain
Hiking store here in Canada. Name brand too. Not absolutely cheap, but
cheap enough. Not every type either. I remember buying some small LED
flashers from the store (intended for bicycle use, but useful as handy
little flashlights since they can be put to a constant on) and thinking
when the button cells died, I'd be buying new flashers, since the
batteries would be as expensive. But the store carries replacement
batteries preciesly for that reason.

For odd batteries, some of the dollar store items can offer up button
cells of various kinds. I was buying 99cent laser pointers for a while to
feed batteries into small clocks and the like I had no problem with the
batteries. But then, I needed some white LEDs for something recently, and
bought a 99cent LED flashlight that offered up 5 white LEDs, Handier than
any other source, probably cheaper too. And it's no wonder those
flashlights often have an LED or two not working; the the LEDs in this
flashlight had one side of the leads twisted together (no solder) and the
other leads hoping to make contact with the case of the flashight for the
return. So it's probably a better source of LEDs than a flashlight.

Michael






==============================================================================
TOPIC: Laser fuser thermal switches?
http://groups.google.com/group/sci.electronics.repair/t/3e3bc34da4e7c0cf?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Jan 14 2014 1:21 pm
From: T i m


On Tue, 14 Jan 2014 09:48:15 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>On Tue, 14 Jan 2014 08:44:28 +0000, T i m <news@spaced.me.uk> wrote:
>
>>>Duz this sound familiar?
>>><http://www.fixyourownprinter.com/forums/printer/72871>
>
>>I'll try the 'impact reset' test and the good thing is you can
>>check the result there and then (with yer DMM).
>
>I rarely see broken mechanical thermostats. More commonly, on HP
>printers, I see accumulated toner residue piled up between the fuser
>roller and the thermostat. Usually, there's some type of film between
>the two, which prevents scratching the drum. I don't think I've ever
>seen a blown thermostat on an HP which makes me wonder if replacing
>the 170C thermostat with an identical Samsung part is a good idea.

Unfortunately without knowing the function / specification of both
parts I'm not sure I have a choice? By that I mean if I was doing such
for someone else, rather than what I might do for myself.
>
>>Yes, I've since spotted that. The problem is though, if they are both
>>thermal switches and of different temperatures (the second / higher to
>>be used more as a failsafe in case the first / normal switch sailed
>>unsafe) then we don't know which one on mine is still functional?
>
>I don't have a schematic,

I have some block / logic diagrams but no schematic. ;-(

It does say this of the fuser though ... (in case it helps).

"....Fuser Ass�y
This unit consists of Heat Roller, a Thermostat and a Thermistor. It
melts and fuses the toner, transferred
by the transfer roller onto the paper, by applying pressure and high
temperature to complete printing job.
* Heat Lamp : Kunckle Type
* Fusing system : 3-Roll Fusing type
- Heat roller : Pipe type (Lamp inside)
- Pressure roller
- Pressure roller Shaft
* Thermistor - Temperature-Measuring Device
* Thermostat - Critical Temperature-Detecting Device
* The life span � 100k(black)/color(25k)

Thermostat
When a heat lamp is overheated, a Thermostat cuts off the main power
to prevent over-heating.
- Non-Contact type Thermostat"

> but I'll guess(tm) that they are running
>some serious heater current through the thermostat, causing the
>contact to possibly arc. A few protective arcs under load, and the
>contacts will build up a layer of oxidized copper which makes a fair
>insulator.

Understood.

>This is the power supply relay contacts of an HP LJII with
>a similar problem:
><http://www.learnbydestroying.com/jeffl/pics/drivel/slides/hp-relay.html>
>The little back dots make great insulators.

Ouch.
>
>Adding a 2nd thermostat sounds like a retrofit to fix the problem.

Not the problem of going o/c I assume?

>There should be a service note on how to do it, somewhere. My
>guess(tm) is that two of the single thermostats will fit, if you can
>find them.

Oh, I'm sure they / I could cover that, if I can find the right fit
and spec parts.
>
>>>Incidentally, on the exploded view of the fuser, there's an
>>>thermistor-NTC which is what probably controls the temperature.
>>
>>Yes, I think I offered / suggested such elsewhere (but didn't know if
>>it was just to provide feedback to the controller board to say 'Warmed
>>up'?
>
>I'm sure it goes to the laser engine controller or power supply.
>That's the way it's usually done on printers that I'm more familiar
>with, such as HP.

The thermistor goes back to the main controller board that is for
sure. I need to have a closer look at the PSU to see if there are any
other connectors from the other boards. Otherwise there is only mains
in and the outputs to the rest of the unit and the fuser. Would the
fuser normally be running at full temperature when the (a) printer was
at idle?
>
>>I've not experienced them till now (normally HPLJ here and still have
>>a trusty P2015dn on our LAN)
>
>Retch. The P2015dn and similar printers are my worst nightmare.

Oh. ;-( Well, I bought it cheap s/h as I wanted a networked b/w
duplex laser and so far <touching wood> it's been ok.

What would you recommend then to cover a similar SOHO, networked
(wired) duplex mono role then Jeff?

>There
>are YouTube videos on how to replace the fuser that should give you a
>clue as to how difficult and time consuming that series of printers
>are to repair.

I'm guessing that like many things (including cars) these days they
are designed to be disposable. ;-(

>I have three of that series printers that are on the
>shelf awaiting repair of the formatter board, which suffers from lousy
>soldering:
><https://www.youtube.com/watch?v=x1acw-7kMws>
><https://www.youtube.com/watch?v=F1q2lmoLUzc>

Luckily I have a mate with all the reflow gear. ;-)
>
>>Cheers and thanks again for all your help.
>
>Good luck and I still don't like Samsung printers.

Thanks and ;-)

Oh, I contacted the supplier of the thermostat pair you kindly found
me and they have replied saying 5 off (minimum quantity) will cost me
80 USD delivered. Now, that's less than the cost of a new fuser but at
least with a new fuser I get a new fuser (as well). ;-)

I've set the printer to idle after 5 mins and will plug it into a
power monitor so I can check to see what sort of current /
background_current it draws then decide from there if I'd want to
leave it on 24/7 or not (as is).

I have 2 x HPLJ 4's that I'm not sure what to do with. They are big,
heavy, non-duplex and neither work properly (electronics faults). I
understand they are (were?) workhorses but they are just so big by
todays SOHO b/w laser standards (one has a JetDirect card fitted).

Cheers, T i m

p.s. I can't seem to get this Samsung to connect via WiFi. It 'sees'
al the local WiFi networks but doesn't want to connect to any (all
mine). The thing that worries me is that although I put the WPA
passphrase in in lower case it displays it in the status printout in
upper?




== 2 of 3 ==
Date: Tues, Jan 14 2014 3:30 pm
From: Jeff Liebermann


On Tue, 14 Jan 2014 21:21:45 +0000, T i m <news@spaced.me.uk> wrote:

>I have some block / logic diagrams but no schematic. ;-(

See if the fuser heater current goes through the thermostat. I
suspect that it does, which means the thermostat has to disconnect
under load. Nice way to create a small arc.

>* Heat Lamp : Kunckle Type

A what?

>Thermostat
>When a heat lamp is overheated, a Thermostat cuts off the main power
>to prevent over-heating.

Main power as in the AC line power? I doubt that. Probably just the
fuser heater power.

>>Adding a 2nd thermostat sounds like a retrofit to fix the problem.
>
>Not the problem of going o/c I assume?

My wild guess(tm) is that the 170C was too low in temperature to stay
closed while the printer was being used as a printing press. The
manufacturer usually recommends a duty cycle, such as 20 mins print,
10 minutes rest, etc which of course, nobody follows. The thermostat
would probably open a few times during such heavy duty printing. The
thermostats are not meant to survive too many such cycles. Rather
than welding the contacts shut, which would be a safety problem, like
a common household circuit breaker, they're made to open at ever
decreasing temperatures, eventually resulting in a permanent open
circuit. Note: this is a guess, this is only a guess.

>Would the
>fuser normally be running at full temperature when the (a) printer was
>at idle?

No. Most laser printers have 3 or 4 levels of power savings. Then
printing, the fuser heater power is full blast. Between print jobs,
usually for about 10 minutes, the power is at about 30% of full blast.
If the printer goes into standby, the fuser power is at about 5-10%
which is just enough to get the first page printed reasonably fast and
avoid major inrush current. In shutdown, the fuser power is totally
off. I have no idea what Samsung does in this printer.

>What would you recommend then to cover a similar SOHO, networked
>(wired) duplex mono role then Jeff?

I like the HP 2300DTN printer.
<http://h20566.www2.hp.com/portal/site/hpsc/public/psi/manualsResults/?cc=us&sp4ts.oid=238800>
I own 3 of them, and have resold or arm twisted customers into buying
approximately 15 of them. The first page comes out in about 3
seconds. Duplex printing is handy to save paper, but is admittedly
slow. However, like all HP printers, these have a lifetime shortening
feature which I believe HP has ignored because it causes obscure late
term failures that sell many replacement printers. Here's the fix:
<http://www.learnbydestroying.com/jeffl/hp2200/hp2200.html>
I've also found the same sticky solenoid problem in all HP printers of
the same vintage (2200, 2230, 4100, 4150, 4200, 4250, 4300, etc).
Also, you might have problems with magnetized solenoids:
<http://www.learnbydestroying.com/jeffl/crud/hp2200-solenoid.wmv>
You'll need an antique 1/4" magnetic tape bulk eraser to fix that.
Otherwise, the 2300dtn have been a great printer.

>I'm guessing that like many things (including cars) these days they
>are designed to be disposable. ;-(

Todays design methodology is actually fairly simple and somewhat
economical. The manufacturer sets a target lifetime for the product.
He then cost reduces components and assembly techniques until
literally everything fails at the same time, somewhat after the target
lifetime. Anything that lasts longer than the target lifetime is
considered a waste of money and is further cost reduced. I can
critique HP's latest laser printer offerings on this basis, but I'm
late for a paying appointment.

>Luckily I have a mate with all the reflow gear. ;-)

I have a hot air SMT desoldering station. It doesn't work. The main
problem is that when the solder is hot enough to reflow, the blowing
air pushes the parts out of position. An IR reflow station is what
you want. However, I pizza oven or electric toaster oven is good
enough.
<https://www.sparkfun.com/tutorials/60>

>Oh, I contacted the supplier of the thermostat pair you kindly found
>me and they have replied saying 5 off (minimum quantity) will cost me
>80 USD delivered. Now, that's less than the cost of a new fuser but at
>least with a new fuser I get a new fuser (as well). ;-)

I think I can find a replacement single thermostat in the US for much
less. Later tonite...

>I have 2 x HPLJ 4's that I'm not sure what to do with.

eWaste.

>p.s. I can't seem to get this Samsung to connect via WiFi. It 'sees'
>al the local WiFi networks but doesn't want to connect to any (all
>mine). The thing that worries me is that although I put the WPA
>passphrase in in lower case it displays it in the status printout in
>upper?

Temporarily clear the WPA encryption key from the wireless router and
see if it will connect with no pass phrase. If that works, try
entering a simple WPA2-AES pass phrase and see if that works. The
usual problem is that some devices enforce the 8 character minimum
pass phrase length, while others ignore it. The other common problem
are Apple Airport base stations that need a firmware update in order
to coexist with other devices. Yet another are web forms that don't
like spaces in the pass phrase. The encryption key can have spaces
but the web form transfers the spaces as garbage. Isn't compatibility
great fun?

Gone...


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558




== 3 of 3 ==
Date: Tues, Jan 14 2014 5:41 pm
From: T i m


On Tue, 14 Jan 2014 15:30:00 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>On Tue, 14 Jan 2014 21:21:45 +0000, T i m <news@spaced.me.uk> wrote:
>
>>I have some block / logic diagrams but no schematic. ;-(
>
>See if the fuser heater current goes through the thermostat. I
>suspect that it does, which means the thermostat has to disconnect
>under load. Nice way to create a small arc.

It does, both, they are in series with the heater / lamp.
>
>>* Heat Lamp : Kunckle Type
>
>A what?

;-) Pass!
>
>>Thermostat
>>When a heat lamp is overheated, a Thermostat cuts off the main power
>>to prevent over-heating.
>
>Main power as in the AC line power? I doubt that. Probably just the
>fuser heater power.

Yup.
>
>>>Adding a 2nd thermostat sounds like a retrofit to fix the problem.
>>
>>Not the problem of going o/c I assume?
>
>My wild guess(tm) is that the 170C was too low in temperature to stay
>closed while the printer was being used as a printing press. The
>manufacturer usually recommends a duty cycle, such as 20 mins print,
>10 minutes rest, etc which of course, nobody follows.

Hehe.

> The thermostat
>would probably open a few times during such heavy duty printing. The
>thermostats are not meant to survive too many such cycles. Rather
>than welding the contacts shut, which would be a safety problem, like
>a common household circuit breaker, they're made to open at ever
>decreasing temperatures, eventually resulting in a permanent open
>circuit. Note: this is a guess, this is only a guess.

Ok ...
>
>>Would the
>>fuser normally be running at full temperature when the (a) printer was
>>at idle?
>
>No. Most laser printers have 3 or 4 levels of power savings. Then
>printing, the fuser heater power is full blast. Between print jobs,
>usually for about 10 minutes, the power is at about 30% of full blast.
>If the printer goes into standby, the fuser power is at about 5-10%
>which is just enough to get the first page printed reasonably fast and
>avoid major inrush current. In shutdown, the fuser power is totally
>off. I have no idea what Samsung does in this printer.

Well, I've set it to 'sleep' after 5 mins and after 30 mins you can
still feel warmth coming out of the paper exit port (I assume that to
also be a thermal vent for the fuser).
>
>>What would you recommend then to cover a similar SOHO, networked
>>(wired) duplex mono role then Jeff?
>
>I like the HP 2300DTN printer.

<Googles> It looks fairly 'chunky'?

><http://h20566.www2.hp.com/portal/site/hpsc/public/psi/manualsResults/?cc=us&sp4ts.oid=238800>
>I own 3 of them, and have resold or arm twisted customers into buying
>approximately 15 of them. The first page comes out in about 3
>seconds. Duplex printing is handy to save paper, but is admittedly
>slow. However, like all HP printers, these have a lifetime shortening
>feature which I believe HP has ignored because it causes obscure late
>term failures that sell many replacement printers.

Oh?

>Here's the fix:
><http://www.learnbydestroying.com/jeffl/hp2200/hp2200.html>

Nice.

>I've also found the same sticky solenoid problem in all HP printers of
>the same vintage (2200, 2230, 4100, 4150, 4200, 4250, 4300, etc).
>Also, you might have problems with magnetized solenoids:
><http://www.learnbydestroying.com/jeffl/crud/hp2200-solenoid.wmv>
>You'll need an antique 1/4" magnetic tape bulk eraser to fix that.

Got one of those. ;-)

>Otherwise, the 2300dtn have been a great printer.
>
>>I'm guessing that like many things (including cars) these days they
>>are designed to be disposable. ;-(
>
>Todays design methodology is actually fairly simple and somewhat
>economical. The manufacturer sets a target lifetime for the product.
>He then cost reduces components and assembly techniques until
>literally everything fails at the same time, somewhat after the target
>lifetime. Anything that lasts longer than the target lifetime is
>considered a waste of money and is further cost reduced. I can
>critique HP's latest laser printer offerings on this basis, but I'm
>late for a paying appointment.

Ok.
>
>>Luckily I have a mate with all the reflow gear. ;-)
>
>I have a hot air SMT desoldering station. It doesn't work. The main
>problem is that when the solder is hot enough to reflow, the blowing
>air pushes the parts out of position. An IR reflow station is what
>you want. However, I pizza oven or electric toaster oven is good
>enough.
><https://www.sparkfun.com/tutorials/60>

Yeah, that's the sort of thing my mate has built / modded / bought
etc.
>
>>Oh, I contacted the supplier of the thermostat pair you kindly found
>>me and they have replied saying 5 off (minimum quantity) will cost me
>>80 USD delivered. Now, that's less than the cost of a new fuser but at
>>least with a new fuser I get a new fuser (as well). ;-)
>
>I think I can find a replacement single thermostat in the US for much
>less. Later tonite...

Oh, cool, thanks (but aren't we still unsure what role both devices
covered? Stat+backup stat. Stat+Overtemp Stat? Stat+Thermal fuse?
>
>>I have 2 x HPLJ 4's that I'm not sure what to do with.
>
>eWaste.

Hmmm, shame.
>
>>p.s. I can't seem to get this Samsung to connect via WiFi. It 'sees'
>>al the local WiFi networks but doesn't want to connect to any (all
>>mine). The thing that worries me is that although I put the WPA
>>passphrase in in lower case it displays it in the status printout in
>>upper?
>
>Temporarily clear the WPA encryption key from the wireless router and
>see if it will connect with no pass phrase. If that works, try
>entering a simple WPA2-AES pass phrase and see if that works. The
>usual problem is that some devices enforce the 8 character minimum
>pass phrase length, while others ignore it.

We have 8+ on all of them. I can do as you suggest but with a spare
router.

>The other common problem
>are Apple Airport base stations that need a firmware update in order
>to coexist with other devices. Yet another are web forms that don't
>like spaces in the pass phrase. The encryption key can have spaces
>but the web form transfers the spaces as garbage. Isn't compatibility
>great fun?

Isn't it just (not). ;-)
>
>Gone...

<looks around>

Whoah, where did Jeff go ...?

Cheers, T i m





==============================================================================
TOPIC: Why would a DECT Panasonic cordless phone keep losing the wireless link?

http://groups.google.com/group/sci.electronics.repair/t/cc34e585e15dfff5?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Jan 14 2014 8:57 pm
From: Tony Matt


On 01/07/2014 10:48 PM, Danny D'Amico wrote:
> When I put the batteries back, I noticed that all five handsets said to
> "Charge for 7 Hours" ...
[...]
> So, something fishy is going on ... with the charge message on the
> handsets ... but I don't know what yet.

Been there, done that, should have posted sooner. These/some Panasonic
cordless handsets display a "Charge for 7 hours" message (and a single
bar on the battery gauge) whenever batteries are installed, regardless
of the state-of-charge.

Details:

Last spring I attempted to set up a used KX-TG9341S system and got this
message on all of the handsets. Old batteries, new batteries, Panasonic
batteries, externally charged batteries, didn't matter (other than
alkaline cells, which it detected: "Wrong battery type"). Measured
voltages, currents, took apart a handset to look for damaged components,
double checked that full battery voltage was actually getting to the
PCB. Googled it, read a bunch of head-scratching, generic battery
advice, and speculation. Got frustrated and moved on to other projects.

A few months later I saw some of the Panasonic NiMH cells at the local
recycling center and decided to take another run at it. I charged
(externally) all of the cells and tested them. Then I got another idea
- I don't normally use AAA NiMH cells, but use lots of AA cells, so
jumpered over a pair of known-good, freshly charged AA cells to the
battery terminals of one of the handsets. Still got the 7 hour message.
That seals it - it's not the batteries. I picked the best six
Panasonic cells, let the handsets go through their 7 hour charge cycle,
and have been using the system ever since.

Panasonic apparently decided to override the charge sense/termination
circuitry with the 7 hour timer when batteries are installed in order to
reduce product returns (from customers who neglect to read the fine
manual and discover that their brand-new handsets and batteries don't
work right away). I did find some weak cells over time, but that's
unrelated to the 7 hour message.

Recommendations:

1. If you put charged cells into the handset, ignore the message and
leave the handset out of the charger for a few days (while using it, of
course). Otherwise, the batteries will be overcharged by the forced
7-hour 'initial' charge.

2. Test for good cells in the handset by trying the speaker phone
option. A weak cell will result in a power cycle (no audio, blank
display, then display with no backlight). If both cells are weak, it
will power cycle when the backlight comes on (i.e. whenever a button is
pressed). Check the cells under load with a meter to determine if one
cell has dropped out, or they are both at low charge. Keep pairs of
cells matched wrt state-of-charge.

3. Look elsewhere for the solution to your link issue.

Good Luck,
Tony Matt




== 2 of 2 ==
Date: Tues, Jan 14 2014 9:04 pm
From: Tony Hwang


Tony Matt wrote:
> On 01/07/2014 10:48 PM, Danny D'Amico wrote:
>> When I put the batteries back, I noticed that all five handsets said to
>> "Charge for 7 Hours" ...
> [...]
>> So, something fishy is going on ... with the charge message on the
>> handsets ... but I don't know what yet.
>
> Been there, done that, should have posted sooner. These/some Panasonic
> cordless handsets display a "Charge for 7 hours" message (and a single
> bar on the battery gauge) whenever batteries are installed, regardless
> of the state-of-charge.
>
> Details:
>
> Last spring I attempted to set up a used KX-TG9341S system and got this
> message on all of the handsets. Old batteries, new batteries, Panasonic
> batteries, externally charged batteries, didn't matter (other than
> alkaline cells, which it detected: "Wrong battery type"). Measured
> voltages, currents, took apart a handset to look for damaged components,
> double checked that full battery voltage was actually getting to the
> PCB. Googled it, read a bunch of head-scratching, generic battery
> advice, and speculation. Got frustrated and moved on to other projects.
>
> A few months later I saw some of the Panasonic NiMH cells at the local
> recycling center and decided to take another run at it. I charged
> (externally) all of the cells and tested them. Then I got another idea
> - I don't normally use AAA NiMH cells, but use lots of AA cells, so
> jumpered over a pair of known-good, freshly charged AA cells to the
> battery terminals of one of the handsets. Still got the 7 hour message.
> That seals it - it's not the batteries. I picked the best six
> Panasonic cells, let the handsets go through their 7 hour charge cycle,
> and have been using the system ever since.
>
> Panasonic apparently decided to override the charge sense/termination
> circuitry with the 7 hour timer when batteries are installed in order to
> reduce product returns (from customers who neglect to read the fine
> manual and discover that their brand-new handsets and batteries don't
> work right away). I did find some weak cells over time, but that's
> unrelated to the 7 hour message.
>
> Recommendations:
>
> 1. If you put charged cells into the handset, ignore the message and
> leave the handset out of the charger for a few days (while using it, of
> course). Otherwise, the batteries will be overcharged by the forced
> 7-hour 'initial' charge.
>
> 2. Test for good cells in the handset by trying the speaker phone
> option. A weak cell will result in a power cycle (no audio, blank
> display, then display with no backlight). If both cells are weak, it
> will power cycle when the backlight comes on (i.e. whenever a button is
> pressed). Check the cells under load with a meter to determine if one
> cell has dropped out, or they are both at low charge. Keep pairs of
> cells matched wrt state-of-charge.
>
> 3. Look elsewhere for the solution to your link issue.
>
> Good Luck,
> Tony Matt
Hmmm,
Maybe I am dumb or simple minded. Manual says charge 7 hours B4 using. I
just left it over night out of box. Ever since they all have been
reliably working. At home and at the store.




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